Method of making bearings and rod end bearings



Sept. 3, 1957 w. D. TRACY METHOD OF MAKING BEARINGS AND ROD END BEARINGSFiled Aug. 25. 1954 Illlllll.

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United States Patent 6 METHOD OF MAKING BEARINGS AND ROD END BEARHWGSWard D. Tracy, Glendora, Calif., assignor to Southwest Products Co.,Duarte, Calif., a corporation of California Application August 23, 1954,Serial No. 451,373

3 Claims. (Cl. 29149.5)

' The present invention relates to an improved bearing structure of theself aligning type and also to an improved method for making the same.

Bearings and rod end bearings of the self aligning type which comprise aball-shaped member rotatably maintained in a race member have beenwidely used in industry. Such self-aligning type of bearings,heretofore, included many different forms and shapes of inserts betweensuch ball-shaped member and the surrounding race member. Many differentproblems are involved arising from the required fitting of theball-shaped member in the race member, and many different devious meanshave heretofore been suggested for solving such problems, some of whichinvolve costly and skilled procedures as well as a finished bearing inwhich the fitting of the ball within the insert left much to be desiredin the way of uniform and accurate dimensional tolerance and an insertwhich covered a large extended projected area of the ball fordistributing stresses over a larger area.

It is, therefore, an object of the present invention to provide animproved method of making bearing structures using an insert between theball and race member that is relatively inexpensive to manufacture, andthat allows maintenance of uniform and accurate dimensional tolerances,and that allows the distribution of stresses over a larger extended areawhereby larger forces may be applied between the ball and the outer racemember particularly in bearings and rod end bearings where it is desiredto accommodate greater axial thrust and vibration.

A specific object of the present invention is to provide a method ofmaking bearing structures of this character in which the race member orthe rod end housing (in the case of a rod end bearing) is preformed withone or more annular inner grooves into which the insert material may bepressed to hold the same therein simultaneously when such insert isbeing coined around a portion of the ball.

Another specific object of the present invention is to provide a methodof making bearing assemblies of this character in which the unitaryinsert is afiixed to the race member at the time the insert is beingcoined around the ball.

Another specific object of the present invention is to provide a simpleand inexpensive method for making or assembling bearing structures ofthis character which is simple and inexpensive to assemble.

Another specific object of the present invention is to provide animproved method of making rod end bearings.

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. This inventionitself, both as to its organization and manner of operation, togetherwith further objects and advantages thereof, may be best understood byreference to the following description taken in connection with theaccompanying drawings in which:

Figure l is a top plan View of a novel bearing manufactured inaccordance with features of the instant invention.

Figure 2 is a sectional view taken substantially on the line 2-2 ofFigure 1.

Figure 3 illustrates the three elements prior to their assembly in theform illustrated in Figures 1 and 2.

Figure 4 illustrates the elements shown in Figure 3 in a press diestructure at the instant the insert is being compressed.

Figure 5 is an illustration similar to that shown in Figure 4 but inthis instance the inner press dies have been moved towards each other todeform the insert.

Figure 6 illustrates a rod end bearing embodying the present invention.

The bearing, which may or may not be a part of a rod end hearing, asshown in Figure 6, illustrated herein includes an outer race member 10,an insert 11, and a ball-shaped bearing member 12, which may have acylindrical apertured portion 12A for fastening purposes. Likewise, ifdesired, the outer race member 10 may be fabricated in various shapes,for example, it may be provided with a threaded stem for use as a rodend bearing, or with an ear, a flange or a pedestal for attachment todifferent members.

The outer race member 12 may be of relatively hard material such ascarbon steel to withstand stress and wear and the same is not deformedin the manufacturing process described below in connection with Figures4 and 5. In accordance with an important feature of the presentinvention such race member 10 which is generally cylindrical orring-shaped is provided with an inner reentrant surface, defined, inthis instance, by one or more inner annular grooved portions 10A and10B. It is within such re-entrant inner surface that the relatively softinsert material is upset, squeezed or crowded in the assembly operationdescribed later.

The insert 11, of relatively soft material, preferably cold workingbearing bronze, originally is as shown in Figures 3 and 4, in the formof a cylindrical tube the outer diameter of which is equal substantiallyto the inner diameter of the race member 10, the inner diameter of thetubular insert 11 being originally substantially equal to the maximumdiameter of the inner ball 12, all as illustrated in Figure 4.

The inner ball 12 is of conventional manufacture and is preferably ofrelatively hard material, such as, for example, carbon steel; and itsdimensions are not altered in the assembly operation.

While the race member 10 is shown in the drawings as having two annulargrooved portions 10A and 10B, it is understood that such operation 10may be provided with only one grooved portion having a width, forexample, as measured along the longitudinal axis of the race member 10,of 7 of an inch (.045 inch) while the depth of such grooved portion maybe, for example, of an inch. Of course, while the use of annular groovedportions is preferred, it is conceivable that less or equal satisfactoryresults may be obtained when the inner surface of the race member 10 ismade re-entrant in accordance with other different patterns.

In the assembly operation, as illustrated in connection with Figures 4and 5, the race member 10 is snugly received within a pair of abuttingannular shouldered members 20 and 21 that serve to hold and confine therace member 10. A pair of circular die presses 22 and 23 are slidablyreceived in the members 20 and 21, and have their adjacent ends dishedto allow respectively an annular shoulder 22A and 23A for contactingopposite ends of the bearing insert 11. The dished portions 22B and 23Bof the press die 22 and 23 are each defined by a radius which issubstantially equal to the radius of the ball 12 so as to obtain thegeneral conformity between the various elements illustrated in Figure 5,at the end of the assembly operation.

After the various elements are assembled, as illustrated in Figure 4,the dies 22 and 23 are both moved toward each other to produce tworesults simultaneously, namely, .(1) a coining of the material of theinsert 11 around the outer periphery of the ball 12, and (2) a crowdingof the material of the insert 11 into the t e-entrant inner surface ofthe race member 10. In other words, some of the material of'the insert11 is caused to move radially in- W y While other po tion of t e i sert11 re cause to move radially outwardly with reference to the axis of theoriginal cylindrical insert 11.

Thus, after the condition illustrated in Figure is achieved, the members20 and 21 may be separated and a m e b g str ture. as il us rated i ure2, is available for use. For all intents andpurposes, the insert 11, inthis condition, may be considered to be integral and a part of the racemember 11).

The forming apparatus illustrated in Figures 4 and 5 may have suchdimensions and may be so manipulated that, the correct desireddimensional tolerance between the insert 11 and the bulb 12 exists; ,oralternatively, the insert 11 may be squeezed to such an extent as tocause the insert material 11 to bind against the ball 12 so that theball 12 may not be free to move. In the latter case, the correctdimensional tolerance between the ball and the race may be establishedusing prior art techniques.

While the particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from this in:vention in its broader aspects, and, therefore, the aim in the appendedclaims is to cover all such changes and modifications as fall within thetrue spirit and scope of this invention.

1 claim:

1. A method of producing a three-piece bearing comprising the steps ofdisposing a one-piece cylindrical insert of relatively soft deformablematerial between a ball and a race having an inner surface contiguouswith an indented portion provided therein and applying a force on eachof the ends of said cylindrical insert to cause material to flowradially into conformity with said ball and to also simultaneously flowradially outwardly against substantially the entire inner surface ofsaid race and into said indented portion of said race, said ends of saidinsert being simultaneously forced into substantially flush relationshipwith the respective ends of said race with substantially no axialmovement of said cylindrical insert with respect to the axis of saidball and said race.

2. A method as set forth in claim 1 in which suificient force is appliedon the ends of said insert to coin said insert around said ball to bindsaid ball against movement in said insert.

3. A method as set forth in claim 1 in which the force applied on theends of said insert is suflicient to cause said insert to conformgenerally with the outer surface of the ball but insuflicient to producebinding between the insert and ball.

References Cited in the file of this patent UNITED STATES PATENTS

